The Dfc is a too low head for it,
The Longranger/Jetranger have long shafts.
You will find the reason the 700 gets used more is due to using the 800 size boom, which means you will run longer blades 790/810's the 600 will not cope with those length of blades, especially on a DFC head which has a low C of G..
You are probably better off putting this in the scale forum there are couple of us who have longrangers and I am currently building a Jetranger/Trex 700 using vario fuse.
I see u have put this in scale forum, will re post more there
All The Best